The tracking of military targets is a central part of many military weapons delivery systems and reconnaissance systems. Examples include the delivery of submissiles from an attack aircraft to target ground armor, the tracking of incoming aircraft and missiles for purposes of self-defense, and the tracking and targeting of one ground vehicle by another.
The autonomous tracking of mobile military ground targets by "smart" weapons is an especially important application area which generally exceeds the capabilities of conventional target trackers. As the smart weapon closes on the selected target, the viewing geometry and target observability radically changes, frequently resulting in loss of target lock.
In the cross referenced system, a canister of submissiles is deployed to a predetermined location over an area of known target concentration and the submissiles are randomly dispensed. As illustrated in FIG. 1, during DEPLOYMENT each submissile orients itself to look straight down at the ground by sensing gravity. During the GROUND LOCK mode, the submissile extracts ground features to estimated its translation and rotation rate with respect to the ground. These rates are used by the submissile's Guidance and Control (G&C) system to lock the submissile onto the ground to reduce motion induced blurring of the imagery. The TARGET ACQUISITION mode examines the submissile's field of view for potential targets. The highest priority target is handed off to the TRACKER resulting in "lock-on" or "target lock". The AIMPOINT SELECTION mode uses target vulnerability knowledge to select an aimpoint which maximized warhead effectiveness. The TRACKING mode is the subject of the present invention.